Author
Topic: 5D3 vs 6D AF in low light (Read 28639 times)

Zlatko

I find its amazing that there are so many posts here that appear to be defending the 5DMk3 ability to focusing ability in low light. Guys, the 5D3 are many things and it has a great focusing system - but its ability to focus in the dark is atrocious, compounded by the lack of a pop up flash i would say it is one of the most significant short comings of the 5D3. Canon recognizing this have improved low light focusing in the 6D and I am sure that every pro dslr released henceforth will be superior to the 5D3 in low light focusing. If this could be improved via firmware I wish canon would fix this. There is no easy solution for this other than to walk around with a flash light. I heard that there was a laser assist someone was working on but i have not seen it.

Most of my photography with the 5D3 is in low light and I find the focusing to be excellent, at least as good as any other camera I've used in the past 10 years. And most Canon flashes have a built-in autofocus assist light, so I don't know why anyone would need a laser assist.

I find its amazing that there are so many posts here that appear to be defending the 5DMk3 ability to focusing ability in low light. Guys, the 5D3 are many things and it has a great focusing system - but its ability to focus in the dark is atrocious, compounded by the lack of a pop up flash i would say it is one of the most significant short comings of the 5D3. Canon recognizing this have improved low light focusing in the 6D and I am sure that every pro dslr released henceforth will be superior to the 5D3 in low light focusing. If this could be improved via firmware I wish canon would fix this. There is no easy solution for this other than to walk around with a flash light. I heard that there was a laser assist someone was working on but i have not seen it.

Most of my photography with the 5D3 is in low light and I find the focusing to be excellent, at least as good as any other camera I've used in the past 10 years. And most Canon flashes have a built-in autofocus assist light, so I don't know why anyone would need a laser assist.

It is obvious that some users experience difficulty in what is to them low enough light where the camera has difficulty in focusing. Saying things like "I shoot alot of low light" doesnt mean anything really... One many lows may be another mans hights, you want a good documented example of what we are talking about see here http://youtu.be/omTo7UxbJX8?t=8m6s. I for one hardly take my flash with me - the camera takes great pictures in low light with some help from lightroom, but getting it to focus sometimes is a problem.

Guys, the 5D3 are many things and it has a great focusing system - but its ability to focus in the dark is atrocious, compounded by the lack of a pop up flash i would say it is one of the most significant short comings of the 5D3.

Pop up flash? Really?? I have used my 5d3 in many low light situations and it has performed fine.

well, then you have to compare your 5dmk3 with another camera, for example 6d and se if there are any differences.

the 6d doesn't have a pop up flash either. I have not laid hands on the 6d yet, but I am considering picking one up as a backup/secondary body. what i will say is that the only time i have had issue with the AF on the mk3 was in situations where I wouldn't have gotten a usable shot anyway! So sorry, i don't really see the issue.

...I for one hardly take my flash with me - the camera takes great pictures in low light with some help from lightroom, but getting it to focus sometimes is a problem.

so....what IS low light to you? are you approaching the EV limits of the AF system, or well within them? These tests are all are very enagaing, but if we could express the level of light in terms of the EV numbering system understood by the photography world, it would be more meaningful. Can someone please explain to me why this is either difficult or unattractive?

Most of the the tests in the video were reasonably done. For example, the guys did a good job of exposing the "snappy" (5D3) versus "heasitant" (D800) AF in the studio, which was revealing, to be sure, especially when acknowledged by the confessed Nikon shooter. Notice he didn't even say anything like "when side by side there is really no important difference", as he did in the shadow DR comparison. for the studio lighting condition the AF performance of the 5D3 was a definate, measureable, and meaningful advantage in real situations.

The low light focusing shootout was disapointing to me because it didn't really test the capabilities of the AF system's thesmselves in low light. All they did was point out that the D800 has an AF assist capability that is useful at reasonable portrait distances when the visible AF assist light is acceptable. Good information, to be sure, but low-light shooters don't necessarily want visible AF assist! What they should have tested is situations where AF assist is either impossible (due to distance) or undesired.

Back to the subject at hand, are you all saying that the 5D3's AF performance in low light (without flash attached) isn't commensurate with the situation, i.e. shutter speeds that would be typical, subject movement etc? Unless I've missed something, the only consistent performance issue meaningfully described here is that camera does not utilize the AF-assist beam from the flash very well.

After experiencing my 200L f/2.8 and how well it focuses in low light vs my 100L with 5D3, I read in the 5D3 manual that the 200L is in AF group A while 100L is in group C, meaning the 200L uses all of the dual cross f/2.8 AF sensors while the 100L uses none of them.

So this explains things since according to p95 of the 6D manual, the 100L apparently uses the maximum capabilities of the 6D center point whereas on the 5D3 Canon has limited the 100L to use only diminished center point capabilities.

Given this, using the 100L to compare the 6D and 5D3 center points was not an apples to apples comparison. And IMO if Canon allows the 100L to use the max capabilities of the 6D center point, Canon needs to offer a firmware fix for the 5D3 and 100L...

"I can focus the 6D's center point on a subject with reasonable contrast down until auto exposure gives me a setting of 160 at 10 seconds and f/2.8 (really dark) with the Canon EF 24-70mm f/2.8 L II USM Lens mounted (note that the 6D's metering range spec is listed at EV 1-20). The Canon EOS 1D X's center point could not focus on the same subject with the same lens mounted. Note that the 6D focuses very slowly under these dismal lighting conditions - but locking slowly is far better than failing to lock."

"Made to focus in very low light condition: EV-3 is the strongest low light AF performance of any Canon AF system at Canon EOS 6D review time. EV-3 is the equivalent of moonlight."

So..1DX has the same AF system as the 5Dmk3.. so 6D does a better job focusing at dark conditions.. better FROM ANY CANON CAMERA TO DATE!

at about 10:50 the reviewer shows a still life shot taken by a 5D3 and 6D at a light level Just short of -3EV? yes, just short of -3EV. ISO 200 15 seconds f/2 is approximately -3EV, so a 13 sec exposure indicates less available light than -3EV, assuming the photo is properly exposed.

this is beyond the AF sensitivity specification listed for the 5D3, which is -2EV for all focus points. It is even (very slightly) beyond the AF sensitivity spec for the 6D, who's center point is spec''d at -3EV sensitivity . Anyway, the reviewer indicated no problems whatsoever with AF for either camera at that light level. However, here's the "but": he didn't say how long it took to achieve AF lock for each camera and he didn't say at what distance the lens was focused prior to locking on the subject. :-(

Most of my photography with the 5D3 is in low light and I find the focusing to be excellent, at least as good as any other camera I've used in the past 10 years. And most Canon flashes have a built-in autofocus assist light, so I don't know why anyone would need a laser assist.

When shooting low key portraits, models don't like it to be dazzled by the assist flash.

When shooting low key portraits, models don't like it to be dazzled by the assist flash.

Animals often also aren't very enthusiastic about getting the af assist in their eye (and that's why I usually focus) - unfortunately the 60d (af rated up to +0.5lv) uses af assist very often, so I'm looking forward to the 6d.

Zlatko

Most of my photography with the 5D3 is in low light and I find the focusing to be excellent, at least as good as any other camera I've used in the past 10 years. And most Canon flashes have a built-in autofocus assist light, so I don't know why anyone would need a laser assist.

When shooting low key portraits, models don't like it to be dazzled by the assist flash.

I was responding to the statement that the 5D3's ability to focus in low light is atrocious. On the contrary, I've found it to be excellent in low light, and that is without any autofocus assist light. However, an autofocus assist light can be used if needed. It is not an "assist flash" and doesn't "dazzle". To clarify, it is the red AF assist light available on most Canon flashes and on the ST-E2. The red AF assist light can be used for AF assist only, with no flash being emitted. The flash is on, but set to not fire. It's not ideal, and it's usually not necessary, but it's available if needed.